I think that you are going to have to make a case for a change in federal law. Require anyone who is providing an electronic messaging service to accept 911 calls at all times. Subscription, credit on cell phone or not. Make refusing to do so a federal offence.

As a point, I had Fire Marshal training last week. Took the oppotunity to have a chat with the serving Fire Officer doing the course. Just to clarify various issues about cellphones and giving position data using a G.P.S.

He tells me that:

In Europe and the U.K. any cellphone that has 999 (U.K. old emergency services no.) or 112 (pan-European) will override the P.I.N. security lock (if in use), lock on to any available network and pass the call. That's with or without credit (for pay as you go tariff's). I understand that this is a "voluntary" agreement between all the service providers.

I don't know what the legal position is in the United States but in the United Kingdom everyone has very specific dutys of care and a case could be made for charging anyone who refuses to render reasonable assistance with endangering life.